Grid structure strength checking method and device

Abstract

The invention belongs to the technical field of structural strength design, and particularly relates to a grating structural strength checking method and device.The method comprises the steps that S1, unit cell material rigidity parameters of grating units are obtained through a finite element model; s2, constructing a grid model of a full-aircraft structure, replacing a grid structure in the full-aircraft structure with a natural grid quadrilateral unit, and assigning a unit cell material rigidity parameter to the natural grid quadrilateral unit; s3, in finite element analysis of the grid model of the full-aircraft structure, extracting stress of a natural grid quadrilateral element; s4, determining an external load applied to the grid units according to the stress of the natural grid quadrilateral units and the size parameters of the grid units; and S5, determining the stress response of the grid unit according to the external load of the grid unit so as to carry out strength checking on the grid structure. According to the method, the calculation time is shortened, and the full-aircraft structure scheme iteration and parameter optimization efficiency is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of structural strength design, and in particular relates to a grid structure strength verification method and device. Background Art

[0002] The existing aircraft grille structure strength verification method mainly establishes a detailed model of the grille structure and connects it to the natural grid model of the whole aircraft for joint solution. The model mesh division quality, unit size, etc. have a great influence on the calculation results, and the establishment and solution of the detailed model are time-consuming. When the structural parameters change, the model needs to be re-established, which is not conducive to variable parameter research, iterative optimization of solutions and other processes. Summary of the invention

[0003] In order to solve the above problems, the present application provides a grid structure strength verification method and device. Through the stiffness equivalence method, the grid structure is equivalent to a natural grid quadrilateral unit to avoid the complex and cumbersome situation caused by establishing a detailed finite element model of the grid unit.

[0004] The first aspect of the present application provides a grid structure strength verification method, which mainly includes:

[0005] Step S1, obtaining the unit cell material stiffness parameters of the grid unit through the finite element model, wherein the grid unit is the smallest repeating unit constituting the grid structure, and the grid structure is a part of the whole machine structure;

[0006] Step S2, constructing a grid model of the whole machine structure, replacing the grid structure in the whole machine structure with natural grid quadrilateral units, and assigning unit cell material stiffness parameters to the natural grid quadrilateral units;

[0007] Step S3, extracting stress of natural grid quadrilateral elements in finite element analysis of the grid model of the whole machine structure;

[0008] Step S4, determining the external load applied to the grid unit according to the stress of the natural grid quadrilateral unit and the size parameters of the grid unit;

[0009] Step S5: determining the stress response of the grid unit according to the external load of the grid unit to perform strength verification on the grid structure.

[0010] Preferably, step S1 further comprises:

[0011] Step S11, establishing a unit cell finite element model of the grid unit, and determining the unit cell size parameters of the grid unit;

[0012] Step S12, applying a specified load to the unit cell finite element model to obtain a relative displacement of the unit cell finite element model;

[0013] Step S13: determining the unit cell material stiffness parameters of the grid unit according to the load, relative displacement and unit cell size parameters.

[0014] Preferably, in step S13, the unit cell material stiffness parameter is determined by the following formula:

[0015]

[0016] Among them, the unit cell material stiffness parameters include the elastic modulus E1 and Poisson's ratio υ along the x direction 21 , elastic modulus E2 and Poisson's ratio υ along the y direction 12 , and the shear modulus G between the x-direction and the y-direction 12 , where the unit cell finite element model is a rhombus structure, the line connecting two opposite vertices of the rhombus is in the x direction, the line connecting the other two opposite vertices is in the y direction, the distance between the two vertices in the x direction is 2a, and the load f in the x direction applied alone x The relative displacement of the two vertices in the x direction is Δu AB1 , the relative displacement of the two vertices in the y direction is Δv CD1 , the distance between the two vertices in the y direction is 2b, and the load f in the y direction is applied alone. y The relative displacement of the two vertices in the x direction is Δu AB2 , the relative displacement of the two vertices in the y direction is Δv CD2 , after the shear force is applied in the x and y directions, the relative displacement of the two vertices in the x direction is Δv AB3 , the relative displacement of the two vertices in the y direction is Δu CD3 , t is the border thickness of the grid unit.

[0017] Preferably, step S3 further includes performing finite element analysis on the mesh model of the entire machine structure, determining the degree of deformation of the natural mesh quadrilateral unit, and evaluating whether the deformation meets the design requirements.

[0018] Preferably, in step S4, the external load applied to the grid unit is determined according to the following formula:

[0019] F x =σ x ×2bt;

[0020] F y =σ y ×2at;

[0021] F xy =τ xy ×t;

[0022] Among them, the external load includes the load F along the x direction x , load F along the y directiony and the shear load F between the x-direction and the y-direction xy , σ x is the strain along the x direction, σ y is the strain along the y direction, τ xy is the shear strain between the x-direction and the y-direction.

[0023] Preferably, in step S5, performing strength check on the grid structure includes:

[0024] If the grid structure is a metal grid, the grid structure is checked by the fourth strength theory; if the grid structure is a composite grid, the grid structure is checked by the maximum strain failure criterion.

[0025] The second aspect of the present application provides a grid structure strength verification device, which mainly includes:

[0026] A unit cell material stiffness parameter determination module is used to obtain the unit cell material stiffness parameters of the grid unit through a finite element model, wherein the grid unit is the smallest repeating unit constituting the grid structure, and the grid structure is a part of the whole machine structure;

[0027] The whole machine structure grid model building module is used to build the grid model of the whole machine structure, replace the grid structure in the whole machine structure with natural grid quadrilateral units, and assign the unit cell material stiffness parameters to the natural grid quadrilateral units;

[0028] Stress extraction module, used to extract stress of natural mesh quadrilateral elements in finite element analysis of mesh models of the whole machine structure;

[0029] An external load calculation module, used to determine the external load applied to the grid unit according to the stress of the natural grid quadrilateral unit and the size parameters of the grid unit;

[0030] The strength checking module is used to determine the stress response of the grid unit according to the external load of the grid unit so as to perform strength checking on the grid structure.

[0031] Preferably, the unit cell material stiffness parameter determination module includes:

[0032] The unit cell finite element model building unit is used to establish the unit cell finite element model of the grid unit and determine the unit cell size parameters of the grid unit;

[0033] A relative displacement extraction unit is used to apply a specified load on the unit cell finite element model to obtain the relative displacement of the unit cell finite element model;

[0034] The unit cell material stiffness parameter calculation unit is used to determine the unit cell material stiffness parameters of the grid unit according to the load, relative displacement and unit cell size parameters.

[0035] Preferably, in the unit cell material stiffness parameter calculation unit, the unit cell material stiffness parameter is determined by the following formula:

[0036]

[0037]

[0038] Among them, the unit cell material stiffness parameters include the elastic modulus E1 and Poisson's ratio υ along the x direction 21 , elastic modulus E2 and Poisson's ratio υ along the y direction 12 , and the shear modulus G between the x-direction and the y-direction 12 , where the unit cell finite element model is a rhombus structure, the line connecting two opposite vertices of the rhombus is in the x direction, the line connecting the other two opposite vertices is in the y direction, the distance between the two vertices in the x direction is 2a, and the load f in the x direction applied alone x The relative displacement of the two vertices in the x direction is Δu AB1 , the relative displacement of the two vertices in the y direction is Δv CD1 , the distance between the two vertices in the y direction is 2b, and the load f in the y direction is applied alone. y The relative displacement of the two vertices in the x direction is Δu AB2 , the relative displacement of the two vertices in the y direction is Δv CD2 , after the shear force is applied in the x and y directions, the relative displacement of the two vertices in the x direction is Δv AB3 , the relative displacement of the two vertices in the y direction is Δu CD3 , t is the border thickness of the grid unit.

[0039] Preferably, the stress extraction module further includes a deformation analysis unit for performing finite element analysis on the mesh model of the entire machine structure, determining the degree of deformation of the natural mesh quadrilateral unit, and evaluating whether the deformation meets the design requirements.

[0040] Preferably, in the external load calculation module, the external load applied to the grid unit is determined according to the following formula:

[0041] F x =σ x ×2bt;

[0042] F y =σ y ×2at;

[0043] F xy =τ xy ×t;

[0044] Among them, the external load includes the load F along the x direction x, load F along the y direction y and the shear load F between the x-direction and the y-direction xy , σ x is the strain along the x direction, σ y is the strain along the y direction, τ xy is the shear strain between the x-direction and the y-direction.

[0045] Preferably, the strength verification module includes:

[0046] A metal grille verification unit is used to verify the grille structure by using the fourth strength theory when the grille structure is a metal grille;

[0047] The composite grating verification unit is used to verify the grating structure by adopting the maximum strain failure criterion when the grating structure is a composite grating.

[0048] A third aspect of the present application provides a computer device, including a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the grid structure strength verification method as described above.

[0049] A fourth aspect of the present application provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, it is used to implement the grid structure strength verification method as described above.

[0050] This application shortens the calculation time and improves the efficiency of overall machine structure scheme iteration and parameter optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a flow chart of a preferred embodiment of the grid structure strength verification method of the present application.

[0052] Figure 2 It is a schematic diagram of the grille structure.

[0053] Figure 3 It is a schematic diagram of the grid unit model.

[0054] Figure 4 It is a schematic diagram of the tensile load applied to the grid unit model.

[0055] Figure 5 It is a schematic diagram of applying shear load to the grid unit model.

[0056] Figure 6 It is a schematic diagram of the finite element model of the entire aircraft structure.

[0057] Figure 7 It is a schematic diagram of the grid area deformation.

[0058] Figure 8 It is a schematic diagram of the structure of a computer device suitable for implementing the embodiments of the present application. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0060] The first aspect of the present application provides a grid structure strength verification method, such as Figure 1 As shown, it mainly includes:

[0061] Step S1, obtaining the unit cell material stiffness parameters of the grid unit through the finite element model, wherein the grid unit is the smallest repeating unit constituting the grid structure, and the grid structure is a part of the whole machine structure;

[0062] Step S2, constructing a grid model of the whole machine structure, replacing the grid structure in the whole machine structure with natural grid quadrilateral units, and assigning unit cell material stiffness parameters to the natural grid quadrilateral units;

[0063] Step S3, extracting stress of natural grid quadrilateral elements in finite element analysis of the grid model of the whole machine structure;

[0064] Step S4, determining the external load applied to the grid unit according to the stress of the natural grid quadrilateral unit and the size parameters of the grid unit;

[0065] Step S5: determining the stress response of the grid unit according to the external load of the grid unit to perform strength verification on the grid structure.

[0066] In step S1, the present application performs finite element analysis on the smallest unit in the grid structure to obtain the unit cell material stiffness parameters of the grid structure. Then, in step S2, the stiffness equivalence method is used to get rid of the tedious problem of establishing and solving the detailed finite element model of the grid unit, and the entire grid structure is replaced with a natural grid quadrilateral unit. Then, in step S3, finite element analysis is performed to obtain the stress acting on the natural grid quadrilateral unit, that is, the stress acting on the grid structure. Then, in step S4, the corresponding external load is calculated. Finally, in step S5, the external load is applied to the grid unit to perform strength verification on the grid unit or the grid structure.

[0067] In some optional implementations, step S1 further includes:

[0068] Step S11, establishing a unit cell finite element model of the grid unit, and determining the unit cell size parameters of the grid unit;

[0069] Step S12, applying a specified load to the unit cell finite element model to obtain a relative displacement of the unit cell finite element model;

[0070] Step S13: determining the unit cell material stiffness parameters of the grid unit according to the load, relative displacement and unit cell size parameters.

[0071] refer to Figure 2 The whole machine structure has an opening area, and a grid structure is arranged in the opening area. According to the periodic characteristics of the structure, the minimum repeating unit (i.e., unit cell) is determined as follows: Figure 3 In the step S11, the unit cell size parameters of the grid unit determined in the diamond beam frame include the diagonal size a and b of the diamond beam frame, and the frame thickness t and height h of the grid unit. According to the unit cell characteristics, it can be simplified as an orthotropic material, and because the size of the grid along the thickness direction is smaller than the size in the plane direction, there are 5 independent unit cell material stiffness parameters: elastic modulus E1 and Poisson's ratio υ along the x direction 21 , elastic modulus E2 and Poisson's ratio υ along the y direction 12 , and the shear modulus G 12 .

[0072] In some optional implementations, in step S13, the unit cell material stiffness parameter is determined by the following formula:

[0073]

[0074]

[0075] Among them, the unit cell material stiffness parameters include the elastic modulus E1 and Poisson's ratio υ along the x direction 21 , elastic modulus E2 and Poisson's ratio υ along the y direction12 , and the shear modulus G between the x-direction and the y-direction 12 , where the unit cell finite element model is a rhombus structure, the line connecting two opposite vertices of the rhombus is in the x direction, the line connecting the other two opposite vertices is in the y direction, the distance between the two vertices in the x direction is 2a, and the load f in the x direction applied alone x The relative displacement of the two vertices in the x direction is Δu AB1 , the relative displacement of the two vertices in the y direction is Δv CD1 , the distance between the two vertices in the y direction is 2b, and the load f in the y direction is applied alone. y The relative displacement of the two vertices in the x direction is Δu AB2 , the relative displacement of the two vertices in the y direction is Δv CD2 , after the shear force is applied in the x and y directions, the relative displacement of the two vertices in the x direction is Δv AB3 , the relative displacement of the two vertices in the y direction is Δu CD3 , t is the border thickness of the grid unit.

[0076] According to the above formula, it can be seen that in step S12, applying the specified load includes applying the load f in the X direction to the established unit cell finite element model separately. x ,like Figure 4 As shown, the relative displacement Δu of points A and B in the X direction is obtained by finite element calculation. AB1 Relative displacement Δv in the Y direction with points C and D CD1 ; and apply the Y-direction load f to the established unit cell finite element model y ,like Figure 4 As shown, the relative displacement Δu of points A and B in the X direction is obtained by finite element calculation. AB2 Relative displacement Δv in the Y direction with points C and D CD2 ; and according to the law of shear stress reciprocity, the shear flow fxy is applied to the established single-cell finite element model, including the shear force 2bfxy at points A and B, and the shear force 2afxy at points C and D, such as Figure 5 As shown, the relative displacement Δv of points A and B in the X direction is obtained by finite element calculation. AB3 Relative displacement Δu in the Y direction with points C and D CD3 .

[0077] Then in step S2, the entire grid structure, i.e. Figure 2 The opening area in is simplified to natural mesh quadrilateral elements, such as Figure 6 As shown, the material properties are planar orthogonal anisotropic MAT8, and the element properties are PCOMP.

[0078] Afterwards, in step S3, a finite element analysis of the grid model of the whole machine structure is performed to obtain analysis results such as stress and deformation of the whole machine including the simplified grid structure.

[0079] In some optional implementations, step S3 further includes performing finite element analysis on the grid model of the entire machine structure to determine the degree of deformation of the natural grid quadrilateral unit and evaluate whether the deformation meets the design requirements. Figure 7 As shown, the stiffness is evaluated based on the deformation to determine whether the deformation requirements are met.

[0080] In step S4, the stress on the natural grid quadrilateral unit is the stress on the grid unit, and based on this, the external load applied to the grid unit can be calculated. In some optional embodiments, in step S4, the external load applied to the grid unit is determined according to the following formula:

[0081] F x =σ x ×2bt;

[0082] F y =σ y ×2at;

[0083] F xy =τ xy ×t;

[0084] Among them, the external load includes the load F along the x direction x , load F along the y direction y and the shear load F between the x-direction and the y-direction xy , σ x is the strain along the x direction, σ y is the strain along the y direction, τ xy is the shear strain between the x-direction and the y-direction.

[0085] Finally, in step S5, the unit cell structure is checked using the corresponding failure criterion. In some optional implementations, in step S5, the strength check of the grid structure includes:

[0086] If the grid structure is a metal grid, the grid structure is checked by the fourth strength theory; if the grid structure is a composite grid, the grid structure is checked by the maximum strain failure criterion.

[0087] For example, the maximum stress of the grid unit extracted from the finite element model of the whole machine is: x =-7.2MPa,σ y =-1.37MPa, τ xy =1MPa, the external load of the unit cell is calculated as:

[0088] Fx =σ x ×2bt=-100.8N

[0089] F y =σ y ×2at=-27.4N.

[0090] F xy =τ xy ×t=1N / mm

[0091] Apply the above loads on the unit cell finite element model and obtain the stress response diagram. mises.max ≤σ b , where σ mises.max is the Mises stress, i.e. the fourth strength equivalent stress, σ b is the strength limit of the material. According to the fourth strength theory, it can be seen that the structure meets the strength requirements.

[0092] The second aspect of the present application provides a grid structure strength verification device corresponding to the above method, mainly comprising:

[0093] A unit cell material stiffness parameter determination module is used to obtain the unit cell material stiffness parameters of the grid unit through a finite element model, wherein the grid unit is the smallest repeating unit constituting the grid structure, and the grid structure is a part of the whole machine structure;

[0094] The whole machine structure grid model building module is used to build the grid model of the whole machine structure, replace the grid structure in the whole machine structure with natural grid quadrilateral units, and assign the unit cell material stiffness parameters to the natural grid quadrilateral units;

[0095] Stress extraction module, used to extract stress of natural mesh quadrilateral elements in finite element analysis of mesh models of the whole machine structure;

[0096] An external load calculation module, used to determine the external load applied to the grid unit according to the stress of the natural grid quadrilateral unit and the size parameters of the grid unit;

[0097] The strength checking module is used to determine the stress response of the grid unit according to the external load of the grid unit so as to perform strength checking on the grid structure.

[0098] In some optional implementations, the unit cell material stiffness parameter determination module includes:

[0099] The unit cell finite element model building unit is used to establish the unit cell finite element model of the grid unit and determine the unit cell size parameters of the grid unit;

[0100] A relative displacement extraction unit is used to apply a specified load on the unit cell finite element model to obtain the relative displacement of the unit cell finite element model;

[0101] The unit cell material stiffness parameter calculation unit is used to determine the unit cell material stiffness parameters of the grid unit according to the load, relative displacement and unit cell size parameters.

[0102] In some optional implementations, in the unit cell material stiffness parameter calculation unit, the unit cell material stiffness parameter is determined by the following formula:

[0103]

[0104] Among them, the unit cell material stiffness parameters include the elastic modulus E1 and Poisson's ratio υ along the x direction 21 , elastic modulus E2 and Poisson's ratio υ along the y direction 12 , and the shear modulus G between the x-direction and the y-direction 12 , where the unit cell finite element model is a rhombus structure, the line connecting two opposite vertices of the rhombus is in the x direction, the line connecting the other two opposite vertices is in the y direction, the distance between the two vertices in the x direction is 2a, and the load f in the x direction applied alone x The relative displacement of the two vertices in the x direction is Δu AB1 , the relative displacement of the two vertices in the y direction is Δv CD1 , the distance between the two vertices in the y direction is 2b, and the load f in the y direction is applied alone. y The relative displacement of the two vertices in the x direction is Δu AB2 , the relative displacement of the two vertices in the y direction is Δv CD2 , after the shear force is applied in the x and y directions, the relative displacement of the two vertices in the x direction is Δv AB3 , the relative displacement of the two vertices in the y direction is Δu CD3 , t is the border thickness of the grid unit.

[0105] In some optional embodiments, the stress extraction module further includes a deformation analysis unit for performing finite element analysis on the mesh model of the entire machine structure, determining the degree of deformation of the natural mesh quadrilateral unit, and evaluating whether the deformation meets the design requirements.

[0106] In some optional implementations, in the external load calculation module, the external load applied to the grid unit is determined according to the following formula:

[0107] F x =σ x ×2bt;

[0108] F y =σ y ×2at;

[0109] F xy =τxy ×t;

[0110] Among them, the external load includes the load F along the x direction x , load F along the y direction y and the shear load F between the x-direction and the y-direction xy , σ x is the strain along the x direction, σ y is the strain along the y direction, τ xy is the shear strain between the x-direction and the y-direction.

[0111] In some optional implementations, the strength verification module includes:

[0112] A metal grille verification unit is used to verify the grille structure by using the fourth strength theory when the grille structure is a metal grille;

[0113] The composite grating verification unit is used to verify the grating structure by adopting the maximum strain failure criterion when the grating structure is a composite grating.

[0114] In a third aspect of the present application, a computer device includes a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement a grid structure strength verification method.

[0115] In a fourth aspect of the present application, a readable storage medium stores a computer program, and when the computer program is executed by a processor, it is used to implement the grid structure strength verification method described above. The computer-readable storage medium may be included in the device described in the above embodiment; or it may exist independently without being assembled into the device. The computer-readable storage medium carries one or more programs, and when the one or more programs are executed by the device, the data is processed according to the above method.

[0116] Reference below Figure 8 , which shows a schematic structural diagram of a computer device 400 suitable for implementing the embodiments of the present application. Figure 8 The computer device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0117] like Figure 8As shown, the computer device 400 includes a central processing unit (CPU) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage part 408 into a random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the device 400 are also stored. The CPU 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0118] The following components are connected to the I / O interface 405: an input section 406 including a keyboard, a mouse, etc.; an output section 407 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, a modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to the I / O interface 405 as needed. A removable medium 411, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 410 as needed, so that a computer program read therefrom is installed into the storage section 408 as needed.

[0119] In particular, according to the embodiment of the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiment of the present application includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 409, and / or installed from the removable medium 411. When the computer program is executed by the central processing unit (CPU) 401, the above functions defined in the method of the present application are executed. It should be noted that the computer storage medium of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium can be, for example, - but not limited to - a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection with one or more conductors, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, an apparatus or a device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in combination with an instruction execution system, an apparatus or a device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0120] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some implementations as replacements, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0121] The modules or units involved in the embodiments described in this application may be implemented by software or hardware. The modules or units described may also be set in a processor, and the names of these modules or units do not constitute limitations on the modules or units themselves in some cases.

[0122] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A grid structure strength verification method, characterized in that: include: Step S1, obtaining the unit cell material stiffness parameters of the grid unit through the finite element model, wherein the grid unit is the smallest repeating unit constituting the grid structure, and the grid structure is a part of the whole machine structure; Step S2, constructing a grid model of the whole machine structure, replacing the grid structure in the whole machine structure with natural grid quadrilateral units, and assigning unit cell material stiffness parameters to the natural grid quadrilateral units; Step S3, extracting stress of natural grid quadrilateral elements in finite element analysis of the grid model of the whole machine structure; Step S4, determining the external load applied to the grid unit according to the stress of the natural grid quadrilateral unit and the size parameters of the grid unit; Step S5: determining the stress response of the grid unit according to the external load of the grid unit to perform strength verification on the grid structure.

2. The grid structure strength verification method according to claim 1, characterized in that: Step S1 further comprises: Step S11, establishing a unit cell finite element model of the grid unit, and determining the unit cell size parameters of the grid unit; Step S12, applying a specified load to the unit cell finite element model to obtain a relative displacement of the unit cell finite element model; Step S13: determining the unit cell material stiffness parameters of the grid unit according to the load, relative displacement and unit cell size parameters.

3. The grid structure strength verification method according to claim 2, characterized in that: In step S13, the unit cell material stiffness parameter is determined by the following formula: Among them, the unit cell material stiffness parameters include the elastic modulus E1 and Poisson's ratio υ along the x direction 21 , elastic modulus E2 and Poisson's ratio υ along the y direction 12 , and the shear modulus G between the x-direction and the y-direction 12 , where the unit cell finite element model is a rhombus structure, the line connecting two opposite vertices of the rhombus is in the x direction, the line connecting the other two opposite vertices is in the y direction, the distance between the two vertices in the x direction is 2a, and the load f in the x direction applied alone x The relative displacement of the two vertices in the x direction is Δu AB1 , the relative displacement of the two vertices in the y direction is Δv CD1 , the distance between the two vertices in the y direction is 2b, and the load f in the y direction is applied alone. y The relative displacement of the two vertices in the x direction is Δu AB2 , the relative displacement of the two vertices in the y direction is Δv CD2 , after the shear force is applied in the x and y directions, the relative displacement of the two vertices in the x direction is Δv AB3 , the relative displacement of the two vertices in the y direction is Δu CD3 , t is the border thickness of the grid unit.

4. The grid structure strength verification method according to claim 1, characterized in that: Step S3 further includes performing finite element analysis on the mesh model of the entire machine structure, determining the degree of deformation of the natural mesh quadrilateral unit, and evaluating whether the deformation meets the design requirements.

5. The grid structure strength verification method according to claim 1, characterized in that: In step S4, the external load applied to the grid unit is determined according to the following formula: F x =s x ×2bt; F y =s y ×2at; F xy =t xy ×t; Among them, the external load includes the load F along the x direction x , load F along the y direction y and the shear load F between the x-direction and the y-direction xy , σ x is the strain along the x direction, σ y is the strain along the y direction, τ xy is the shear strain between the x-direction and the y-direction.

6. The grid structure strength verification method according to claim 1, characterized in that: In step S5, the strength check of the grid structure includes: If the grid structure is a metal grid, the grid structure is checked by the fourth strength theory; if the grid structure is a composite grid, the grid structure is checked by the maximum strain failure criterion.

7. A grid structure strength verification device, characterized in that: include: A unit cell material stiffness parameter determination module is used to obtain the unit cell material stiffness parameters of the grid unit through a finite element model, wherein the grid unit is the smallest repeating unit constituting the grid structure, and the grid structure is a part of the whole machine structure; The whole machine structure grid model building module is used to build the grid model of the whole machine structure, replace the grid structure in the whole machine structure with natural grid quadrilateral units, and assign the unit cell material stiffness parameters to the natural grid quadrilateral units; Stress extraction module, used to extract stress of natural mesh quadrilateral elements in finite element analysis of mesh models of the whole machine structure; An external load calculation module, used for determining the external load applied to the grid unit according to the stress of the natural grid quadrilateral unit and the size parameters of the grid unit; The strength checking module is used to determine the stress response of the grid unit according to the external load of the grid unit so as to perform strength checking on the grid structure.

8. The grid structure strength checking device according to claim 7, characterized in that: The unit cell material stiffness parameter determination module includes: A unit cell finite element model building unit is used to build a unit cell finite element model of a grid unit and determine the unit cell size parameters of the grid unit; A relative displacement extraction unit is used to apply a specified load on the unit cell finite element model to obtain the relative displacement of the unit cell finite element model; The unit cell material stiffness parameter calculation unit is used to determine the unit cell material stiffness parameters of the grid unit according to the load, relative displacement and unit cell size parameters.

9. The grid structure strength checking device according to claim 8, characterized in that: In the unit cell material stiffness parameter calculation unit, the unit cell material stiffness parameter is determined by the following formula: Among them, the unit cell material stiffness parameters include the elastic modulus E1 and Poisson's ratio υ along the x direction 21 , elastic modulus E2 and Poisson's ratio υ along the y direction 12 , and the shear modulus G between the x-direction and the y-direction 12 , where the unit cell finite element model is a rhombus structure, the line connecting two opposite vertices of the rhombus is in the x direction, the line connecting the other two opposite vertices is in the y direction, the distance between the two vertices in the x direction is 2a, and the load f in the x direction applied alone x The relative displacement of the two vertices in the x direction is Δu AB1 , the relative displacement of the two vertices in the y direction is Δv CD1 , the distance between the two vertices in the y direction is 2b, and the load f in the y direction is applied alone. y The relative displacement of the two vertices in the x direction is Δu AB2 , the relative displacement of the two vertices in the y direction is Δv CD2 , after the shear force is applied in the x and y directions, the relative displacement of the two vertices in the x direction is Δv AB3 , the relative displacement of the two vertices in the y direction is Δu CD3 , t is the border thickness of the grid unit.

10. The grid structure strength checking device according to claim 7, characterized in that: The stress extraction module also includes a deformation analysis unit, which is used to perform finite element analysis on the grid model of the entire machine structure, determine the deformation degree of the natural grid quadrilateral unit, and evaluate whether the deformation meets the design requirements.

11. The grid structure strength checking device according to claim 7, characterized in that: In the external load calculation module, the external load applied to the grid unit is determined according to the following formula: F x =s x ×2bt; F y =s y ×2at; F xy =t xy ×t; Among them, the external load includes the load F along the x direction x , load F along the y direction y and the shear load F between the x-direction and the y-direction xy , σ x is the strain along the x direction, σ y is the strain along the y direction, τ xy is the shear strain between the x-direction and the y-direction.

12. The grid structure strength checking device according to claim 7, characterized in that: The strength verification module comprises: A metal grille verification unit is used to verify the grille structure by using the fourth strength theory when the grille structure is a metal grille; The composite grating verification unit is used to verify the grating structure by adopting the maximum strain failure criterion when the grating structure is a composite grating.

13. A computer device, characterized in that: The method comprises a processor, a memory and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the grid structure strength verification method according to any one of claims 1 to 6.

14. A readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, it is used to implement the grid structure strength verification method as described in any one of claims 1 to 6.

Images